1. Field of the Invention
The present invention relates in general to pressure transducers and pertains, more particularly, to a pressure transducer that is adapted to sense pressure by optical means.
2. Background Discussion The assignee of the present application presently manufacturers and sells melt pressure transducers that are covered by one or more of the following United States patents:
______________________________________ U.S. Pat. No. Issued ______________________________________ 3,349,623 October 31, 1967 3,678,753 July 25, 1972 4,680,972 July 21, 1987 4,679,438 July 14, 1987 4,702,113 October 27, 1987 4,712,430 December 15, 1987 4,829,827 May 16, 1989 4,819,487 April 11, 1989 4,858,471 August 22, 1989 ______________________________________
For the most part, these pressure transducer constructions use a liquid metal filled capillary system. A typical fill material is mercury. For some applications, particularly where toxicity could be critical, mercury filled pressure transducers may be considered somewhat unsafe in operation.
Accordingly, it is an object of the present invention to provide an alternative pressure sensor construction which eliminates the need for a liquid metal filled capillary system and which is yet able to operate in harsh, high temperature/pressure working environments.
Another object of the present invention is to provide an optical pressure transducer which permits the signal conditioning electronics to be disposed remote to the working environment without loss of signal integrity.
A further object of the present invention is to provide an improved optical pressure transducer that can be constructed in relatively small size, particularly adapted for essential retrofit in a standard melt pressure transducer framework.